Dialing authorization is definitely one of the main concerns of any PBX Administrator, maybe even more now that the economy is forcing most companies to reduce costs.
Since Office Communications Server (OCS) 2007 R2 has all the necessary telephony capabilities to replace the PBX, it should offer the same dialing control as those legacy PBX’s… And it does!
Before diving into further detail, let’s first introduce some terminology and concepts associated with OCS:
In order to define different levels of dialing privileges, we must create different Voice Policies (that must be assigned to the different users), which in turn control the access to the outbound Routes. And in the end, it’s all about the Routes, Routes act as the Checkpoint Charlie of outbound calls: if a user is configured with a Voice Policy, that contains a certain Phone Usage, that is associated with a Route for the dialed number, then the call is successfully placed.
Confused? I’ll give you an example shortly, but before, take a look at this diagram from Microsoft TechNet site User Authorization and Outbound Call Routing Requirements:
From my field experience, I noticed there is more or less a pattern from all my customers regarding the types of outbound call privileges, which is:
This simple practical example will cover a single location with a single point of exit to the PSTN. It will be relatively easy to derivate from this sample example and build more complex scenarios.
If you noticed the above diagram, the first step is to define the location profile(s) and to configure normalization rules, which I won’t cover in this post (if you want to know the details, please read Location Profiles and Normalization Rules).
So I’ll start instead from the Phone Usage Records definition. The picture below depicts the 5 phone usage records created in this practical example, one for each of the outbound calling privileges described previously.
The next step is to create the corresponding voice policies. Once again there is a voice policy for each of the phone usage created previously, as depicted in the following picture:
Notice that Use per user policy is selected, as opposed to selecting a default global policy, since we want to differentiate the privileges each user has.
Since the users with more dial out privileges must also be able to place less privileged calls (users allowed to dial mobile numbers can also dial internal extensions, for example), the more “advanced” policies must include the less privileged phone usages, as the following pictures illustrate.
The final step is to create the voice routes, and once again, there will be one route for each phone usage, plus one for the emergency number. The following table provides a brief explanation of the different routes configured:
Here’s an image of the Routes tab from the OCS Voice Properties dialog box:
Each route has only the corresponding phone usage associated, except the emergency route, which has all the configured phone usages, as illustrated below:
Now that everything is in place, we need to test if the different configured user profiles work as expected. There is a neat tool, part of the Microsoft Office Communications Server 2007 Resource Kit Tools that really suits this task: Enterprise Voice Route Helper. For detailed instructions on how to use the tool, there is a comprehensive user’s guide available to download.
All the different combinations between voice policies and the different possible outbound numbers should be tested, but for demonstration purposes I’ll use only 2 test cases:
For the first scenario the call is permitted and routed out, as you can see in the following picture:
As for the second test case, the call is blocked, with the message “Unable to route”.
For more details regarding Enterprise Voice planning and configuration, please read the following technical information from the TechNet site: